Stabilized hydrocarbon distillate



2,974,023 STABHLIZED HYDROCARBON DISTILLATE Henry A. Cyba, hicago, andRalph R. Thompson, Hinsdale, 11., assiguors, by mesne assignments, toUniversal Oil Products Company, Des Plaines, llh, a corporation ofDelaware No Drawing. Filed June 14, 1956, Ser. No. 591,295 9 Claims.(Cl. 44-62) This invention relates to the stabilization of organiccompounds and more particularly to a novel process for preventingdeterioration of said organic compounds in storage, duringtransportation or in use.

The present invention is particularly advantageous for use in thestabilization of a hydrocarbon distillate and serves to improve thehydrocarbon distillate in a number of different ways. For example, infuel oils, burner oils, range oils, diesel oils, marine oils, turbineoils, cutting oils, rolling oils, soluble oils, drawing oils, slushingoils, slushing greases, lubricating oils, lubricating greases,fingerprint removers, etc., the distillate or grease is improved in oneor more ways including retarding and/or preventing sediment formation,dispersion of sediment when formed, preventing and/or retardingdiscoloration, oxidation inhibitor, rust or corrosion inhibitor,detergent, etc. Inlubricating type oils, in addition to all or some ofthe properties hereinbefore set forth, the additive may function as apour point depressant, viscosity index improver, anti-foaming agent,extreme pressure additive, etc. In liquefied petroleum gases, gasoline,naphtha, aromatic solvents, kerosene, jet fuels, etc., the additiveserves as a corrosion inhibitor along with one or more of the otherfunctions mentioned above. In other organic compounds, includingalcohols, ethers, aldehydes, ketones, chlorinated hydrocarbons, etc.,and compositions containing them, glycen'dic oils and fats, waxes, otheroils and fats of animal or vegetable origin, rubber, resins, plastics,etc., the additive functions as a beneficient in one or more of themanners herein set forth or otherwise.

The invention is particularly applicable to the stabilization ofhydrocarbon distillates heavier than gasoline. The hydrocarbondistillate may be cracked, straight run or mixtures thereof. Many fueloils and particularly blends of straight run and cracked fuel oilsundergo deterioration in storage, resulting in the formation ofsediment, dis-,

coloration, etc. The formation of sediment is objectionable because thesediment tends to plug burner tips, injectors, etc. In diesel fuel, thedeterioration tends to form varnish and sludge in the diesel engine.Discoloration of fuel oils is objectionable for various reasons,including customers preference for light colored oils.

In handling of hydrocarbon distillates and other organic liquids, it isoften necessary to transport and/or store such materials in metalcontainers, as in steel or other metal pipe lines, drums, tanks, etc.Since these materials often contain varying amounts of water in solutionor in suspension which may separate, due to temperature changes,internal corrosion of the container by separating water almostinvariably occurs to a greater or lesser degree. The water thusseparated forms as a film or in minute droplets in the pipe line or onthe container Walls or even in small pools at the bottom of the corntainer. This brings about ideal conditions for corrosion and consequentdamage to the metal surfaces of the container, as well as the seriouscontamination of the hydro ,N-docosyl-diethanolamine,

carbon oil or other materials contained therein by the corrosionproducts.

Corrosion problems also occur, for example, in the lubrication ofinternal combustion engines or steam engines, including turbines andother similar machinery, in which a quantity of Water is often observedas a separate phase within the lubricating system as a result of thecondensation of water from the atmosphere or, in the case of internalcombustion engines, as the result of dispersion or absorption inlubricating oil of Water formed as a product of fuel combustion. Waterin such instances corrodes the various metal parts of the machinery withwhich it comes into contact, the corrosion products causing furthermechanical damage to bearing surfaces and the like due to their abrasivenature and catalytically promoting the chemical degradation of thelubricant. Corrosion problems also arise in the preparation,transportation and use of various coating compositions such as greases,household oils, paints, lacquer, etc., which often are applied to metalsurfaces for protective purposes.

In one embodiment the present invention relates to a process forstabilizing an organic substrate against deterioration which comprisesincorporating therein a stabilizing concentration of an inhibitorcomprising the condensation product of a dialkanolamine with thereaction product of a terpene and a compound selected from the groupconsisting of an alpha, beta-unsaturated polycarboxylic acid, anhydrideand ester thereof. I

In a specific embodiment the present invention relates to thestabilization of a hydrocarbon distillate which comprises incorporatingtherein a stabilizing concentration of the condensation product ofN-talloW-diethanolarninc with the reaction product of a terpene andmaleic anhydride.

The additive for use in the present invention is formed by thecondensation of a dialkanolamine and particularly anN-aliphatic-dialkanolamine with a polycarboxylic acid, anhydride orester formed by the reaction of a terpenic compound with an alpha,beta-unsaturated polycarboxylic acid, anhydride or ester thereof.

Any suitable dialkanolamine is used in acoordancewith- Preferably thedialkanolamine is I not more than 4 carbon atoms.

A particularly preferred N-substituted dialkanolamine comprises anN-alkyl-diethanolamine. pounds include N-heXyl-diethanolamine,N-heptyl-diethanolamine, N-octyl-diethanolamine, N-nonyl-diethanolamine,N-decyl-diethanolamine, N-undecyl-diethanolamine,N-dodecyl-diethanolamine,

' N-tridecyl-diethanolamine,

N tetradecyl-diethanolamine, N-pentadecyl-diethanolamine,N-hexadecyl-diethanolamine, N-heptadecyl-diethanolamine,N-octadecyl-diethanolamine, N-nonadecyl-diethanolamine,N-eicosyl-diethanolamine, N-heneicosyl-diethanolamine,

Patented Marfli, 1961 Illustrative com- N-tricosyl-diethanolamine,N-tetracosyl-diethanolamine,

N-p entacosyl-diethanolamine, N-hexacosyl-diethanolamine,N-heptacosyl-diethanolamine, N-octacosyl-diethanolamine,N-nonacosyl-diethanolamine, N-triacontyl-diethanolamine,N-hentriacontyl-diethan olamine, N-dotriacontyl-diethanolamine,N-tritriacontyl-diethanolamine, N-tetratriacontyl diethanolamine,N-pentatriacontyl-diethanolamine, N -hexatriacontyl-diethanolamine,N-heptatriacontyl-diethanolamine, N-oetatriacontyl-diethano1amine,N-nonatriacontyl-diethanolamine, N-tetracontyl-diethanolamine,N-hentetraoontyl-diethano-lamine, N-dotetracontyl diethanolamine,N-tritetracontyl-diethanolamine, N-tetratetracontybdiethanolamine,N-pentatetracontyl-diethanolamine, N-hexatetracontyl-diethanolamine,N-heptatetracontyLdiethanolamine, N-octatetracontyl-diethanolamine,N-nonatetracontyl-diethanolamine, N-pentacontyl-diethanolamine, etc.

In some cases, N-alkenyl-diethanolamines may be utilized. IllustrativeN-alkenyl-diethanolamines include N-heXenyl-diethanolamine,N-heptenyl-diethanolamine, N-octenyl-diethanolamine,N-nonenyl-diethanolamine, N-decenybdiethanolamine,N-undecenyl-diethanolamine, N-dodecenyl-diethanolamine,N-tridecenyl-diethanolamine, N-tetradecenyl-diethanolamine,N-pentadecenyl-diethanolamine, N-hexadecenyl-diethanolamine,N-heptadecenyl-diethanolamine, N-octadecenyl-diethanolamine,N-nonadecenyl-diethanolamine, N-eicosenyl diethanolamine, etc.

It is understood that the N-aliphatic-diethanolamines may containaliphatic substituents attached to one or both of the carbon atomsforming the ethanol groups. These compounds may be illustrated byN-aliphatic-bis- 2-hydroxy-3 -heptyl) -amine,

N-aliphatic-bis- (2-hydroXy-3 -octyl) -amine, etc.

It will be noted that, although named as an amine or alkanol, thesecompounds are diethanol-amines as they contain two groups having theethanol and amine groupings. It is understood that these specificcompounds are illustrative only and that other suitable compounds containing the diethanolamine configuration may be-employed.

beta carbon atoms may be employed.

tuted in a manner similar to that specifically described hereinbefore inconnection with the discussion of the diethanolamines. Furthermore, itis understood that mixtures of N-aliphatic-dialkanolamines may beemployed, 7

preferably being selected from those hereinbefore set forth. Also, it isunderstood that the various dialkanolamines are not necessarilyequivalent.

A number of N-alkyl-diethanolamines are available commercially. Forexample, N-tallow-diethanolamine is available under the trade name ofEthomeen T/ 12. This material is a gel at room temperature, has anaverage molecular weight of 354 and a specific gravity at 25/25 C. of0.916. The alkyl substituents contain from about 12 to 20 carbon atomsper group and mostly 16 to 18 carbon atoms. Another mixed product isavailable commercially under the trade name of Ethomeen S/ 12 and isN-soya-diethanolamine. it is a gel at room temperature, has an averagemolecular weight of 367 and a specific gravity art 25/ 25C. of 0.911.The alkyl substituents contain 16-18 carbon atoms per group. Stillanother commercial product is Ethomeen C/12, which isN-coco-diethanolamine and is a liquid at room temperature, has anaverage molecular weight of 303 and a specific gravity at 25/25 C., of0.874. The alkyl group contains mostly-12 carbon atoms per group,although it also contains groups having from 8 to 16 carbon atoms pergroup. Still another commercially available product isN-stearyl-diethanolamine, which is marketed under the trade name ofEthomeen 18/ 12. This product is a solid at room temperature, has anaverage molecular weight of 372 and a specific gravity at 25/ 25 C. of0.959. It contains 18 carbon atoms in the alkyl substituent. It isunderstood that these dialkanolamines may be employed in accordance withthe present invention.

As hereinbefore set forth, the N-aliphatic-dialkanolamine-is reactedwith a polycarboxylic acid, anhydride or ester formed by the reaction ofa terpene with an alpha, beta-unsaturated polycarboxylic acid, anhydrideor ester. The reaction product will comprise primarily the anhydride butthe acid and/ or ester also will be present. Any suitableterpenic-compound may be reacted with any suitablealpha,beta-unsaturated polycarboxylic acid, an? hydride or ester to formthe reaction product for subsequent' condensation with thepolyalkarrolamine. In one embodiment a terpene hydrocarbonhaving theformula C f-I is employed, including alpha-pinene, beta-pinene,dipentene, d-limonene, l-limonene and terpinoline. These terpenehydrocarbons have boiling points ranging from about to about C. Inanother embodiment the terpene may contain three double bonds inmonomeric form, including terpenes as allo-o-cymene, o-cymene, myrcene,etc. terpinene, p-cymene, etc. pounds are rosins comprising the terpenichydrocarbons and/or terpenic acids. are tricyclic compounds. However,they are obtained from pine trees and therefore-may be included in thebroad classification as terpene orterpenic compounds.

As hereinbefore set forth, the rterpene is reacted with analpha,beta-unsaturated polycarboxylic acid, anhydride or ester thereof.-Any unsaturated polycarboxylic acid having a point of unsaturationbetween the alpha and Illustrative unsaturated dicarboxylic acidsinclude maleic acid,'fumaric acid, citraconic acid,',mesaconic acid,aconitic acid, itaconic acid, etc. While the dicarboxylic acids are preferred, it is understoodthat alpha,beta-unsaturatedpoly- Other teipeniccompounds include alpha- Also included as terpenic com- T hese rosinsand acids generally acmpaa carboxylic acids containing three, four ormore carboxylic acidgroupsmay be employed. Furthermore, it

is understood that a mixture of alpha,beta-unsaturated polycarboxylicacids and particularly of alpha,beta-unsaturated dicarboxylic acids maybe used.

While the alpha,beta-unsaturated polycarboxylic acid may be employed,advantages appear to be obtained in some cases when using the anhydridesthereof. Illustrative anhydrides include maleic anhydride, citraconicanhydride, aconitic anhydride, itaconic anhydride, etc. It is understoodthat a mixture of anhydrides may be employed and also that the anhydridemay contain substituents and particularly hydrocarbon groups attachedthereto. Furthermore, it is understood that the various anhydrides arenot necessarily equivalent. Also, it is understood that esters of thealpha,beta-unsaturated polycarboxylic acids may be employed, the estergroup being selected from alkyl, alkaryl, aralkyl, aryl and cycloalkylsubstituents replacing one or more of the hydrogen atoms of thecarboxylic acid groups.

The reaction of terpene and alpha,beta-unsaturated acid, anhydride orester generally is eifected at a temperature of from about 150 to about300 C., and preferably of from about 160 to about 200 C. The time ofheating will depend upon the particular reactants and may range from 2hours to 24 hours or more. When desired, a' suitable solvent may beutilized. Following the reaction, impurities or unreacted materials maybe removed by vacuum distillation or otherwise, to leave a resinousproduct which may be a viscous liquid or a solid.

A terpene-maleic anhydride reaction product is available commerciallyunder the trade name of Petrex Acid. This acid is a stringy,yellow-amber colored mass and is mostly dibasic. It has an acid numberof approximately 530, a molecular weight of approximately 215 and asoftening point of 40-50 C.

Another reaction product is available commercially under the trade nameof Lewisol 40 Acid. This is a tricarboxylic acid and is formed by thereaction of fumaric'acid and rosin. It is a hard, brittle solid having asoftening point of 150-l60 C. and a specific gravity at 25/25 C. of1.178.

-.The condensation of the dialkanolamine and reaction product ofterpeneand alpha,beta-unsaturated polycarboxylic acid, anhydride orester may be elfected in any suitable manner. The reaction generally iseffected at a temperature above about 80 C. and preferably at a highertemperature which usually will not exceed about 200 C., although higheror lower temperatures may be employed under certain conditions. Theexact tempera ture will depend upon whether a solvent is used and, whenemployed, on the particular solvent. For example, with benzene as thesolvent, the temperature will be in the order of 80 C., with toluene thetemperature will be in the order of 120 C., and with xylene in the orderof 150l55 C. Other preferred solvents include cumene, naphtha, decalin,etc. Any suitable amount of the solvent may be employed but preferablyshould not comprise a large excess because this will tend to lower thereaction temperature and slow the reaction. Water formed during thereaction may be removed in any suitable manner including, for example,by operating under reduced pressure, by removing an azeotrope ofwatersolvent, by distilling the reaction product at an elevatedtemperature, etc. A higher temperature may be utilized in effecting thereaction in order to remove the water as it is being formed. However,for many uses, the reaction need not go to completion, but in any eventat least a substantial portion of the reaction product will comprisethat formed by the condensation of the polyalkanolamine with theterpene-acid, anhydride or ester reaction product.

In general, the condensation is effected using equivalent acid orpotential acid groups per total hydroxyl groups. However, it isunderstood that the total acid or potential acid groups may range fromabout 0.5 to about 2 equivalents thetreof per equivalent of totalhydroxyl groups.

From the above description, it will be noted that a number of differentcompounds may be prepared and used in accordance with the presentinvention, and will depend upon specific dialkanolamine. andterpene-acid, anhydride or ester reaction product used in thecondensation reaction. However, it is understood that, While all ofthese compounds will be effective in certain substrates, all are notnecessarily equivalent in the same or different substrate.

The condensation product is recovered as a viscous liquid or solid. Insome cases, the product will be marketed and utilized as a solution in asolvent. Conveniently, this solvent comprises the same solvent used inpreparing the condensation product and is recovered in admixture with atleast a portion of the solvent, thereby avoiding the necessity ofremoving all of the solvent and subsequently adding it back. When a moredilute solution is desired than is recovered in the manner hereinbeforeset forth, it is understood that the same ordifferent solvent may becommingled with the mixture to form a solution of the desiredconcentration.

The concentration of additive to be used in the organic substrate willdepend upon the particular substrate and the particular benefitsdesired. In general, the additive will be used in a concentration offrom about 0.00001% to about 5% by weight or more and more specificallyis used in a concentration of from about0.0001% to about 1% by weight ofthe substrate. The additive may be used along with other additives whichare incorporated in a substrate for specific purposes including, forexample, metal deactivators, antioxidants, antiozidants, synergists,dyes, fuel improvers, etc.

The additive is incorporated in the substrate in any suitable manner. Ashereinbefore set forth, the additive conveniently is marketed as asolution in a suitable sol vent, including hydrocarbons and particularlyaromatic hydrocarbons as benzene, toluene, xylene, cumene, etc. When theadditive is to be incorporated in a liquid substrate, it is addedthereto in the desired amount and the resultant mixture suitablyagitated or otherwise mixed in order to obtainintimate admixing of theadditive in the substrate. When the additive is to be utilized as acorrosion inhibitor in plant equipment, it may be introduced into afractionator, vapor line or at anyother suitable point in order toprevent corrosion of the plant equipment. In this embodiment, theadditive carries over into the product of the process and also servestherein as a beneficent. It is understood that a portion of the additivemay be introduced into the plant equipment and an additional portion ofthe additive incorporated in the effiuent product when so desired.

The following examples are introduced to illustrate further the noveltyand utility of the present invention but not with the intention ofunduly limiting the same.

A number of additives were prepared and were tested by two differentmethods. 'In one method, referred to as the Fuel Oil Suspension Test,powdered carbon black (aboutl /z cc.) is shaken with cc. of fuel oil for2 minutes. At a period up to a Week, a settling slowly occurs. Aneffective additive retards the settling and maintains the sedimentdispersed throughout the oil. As hereinbefore set forth, dispersing thesediment throughout the fuel oil allows the sediment to pass throughfilters, burner tips, etc., whereas sedimentation will result inclogging of the fuel oil lines, filters, burner tips, etc.

In still another test, referred to as the Erdco Test, heated oil ispassed through a filter and the time required-to develop a differentialpressure across the filter of 25 in. Hg is determined. the time, themore effective is the additive. However, with a very effective additive,the time to reach a differ-V ential pressure across the filter of 25 in.Hg is lengthened It is apparent that the longer beyond reasonable limitsthat the test is .stopped after about 250 minutes and the differentialpressure at that time is reported.

Example I The additive used in this example was prepared by thecondensation of 1 equivalent of N-tallow-dieth'anolamine (Ethomeen T/12)with 1 equivalent-of Petrex Acid. As hereinbefore set forth,N-tallow-diethanolamine is a mixed N-aliphatic-diethanolamine containingfrom 12 to 20 carbon 'atoms in the alkyl group and mostly 16 to 18carbon atoms. Also, as hereinbefore set forth Petrex Acid is thereaction product of terpene and rnaleic anhydride, and the properties ofthis acid have been set forth previously. The condensation was effectedin substantially the same manner as hereinbefore described. Xylene wasused as the solvent and the mixture was refluxed at 155 165 C. for 8hours. When no more water was evolved, the solvent was removed bypumping in vacuo, ending with a temperature of 100 C. at 1 mm. pressure.

The above condensation product was prepared as a solution in toluene and0.02% by weight (based on active ingredient) was incorporated in 100 cc.of a #2 fuel oil and tested according to 'the Fuel Oil Suspension Testheretofore described. When evaluated according to this test, the fueloil containing this additive was reported as good. In contrast, acontrol sample of the fuel oil (sample not containing this additive),when evaluated in this test, was reported as poor. As hereinbefore setforth, the results reported as good mean that the carbon black wasmaintained in suspension and did not settle out. On the other hand, theresults reported as poor mean that the carbon black settled out ofsolution and therefore would plug filters, burner tips, etc., duringuse.

Example II Another sample of the condensation product prepared in themanner described in Example I was utilized in The heated oil used inthis test was.

the Erdco Test.

a commercial range oil. 0.01% by weight of the condensation productdescribed in Example I was incorporated in a sample of the oil and runin the Erdco Test. After 300 minutes, the differential pressure acrossthe filter was only 0.2 in. Hg. On the other hand, a

control sample (not containing this additive) reached a differentialpressure across the filter of '25 in. Hg in about 78 minutes.

Example III mostly 12 carbon atoms per group in the alkyl substit--uent. The condensation was effected in substantially the same manner asdescribed in Example I.

incorporated in a #2 fuel oil and tested according to the Fuel OilSuspension Test. Theresults of this testwere reported as good. Hereagain, it will be noted that the additive served to improve the fueloil.

Example V reported as good, which means that the additive'servedto'irnprove thefuel oil and will prevent clogging of the filters, burnertips, etc. during use.

Example V1 p The additive used in this example is prepared by thecondensation of 1 equivalent of N-hexadecyl-diethanolamine withlequivalent of 'Lewisol 40 Acid; The properties of this acid have beenset forth hereinbefore. The condensationis, effected in substantiallythe same manner as hereinbefore set forth/using xylene as the solvent.Following completion of the. reaction, the xylene is removed by vacuumdistillation, and the condensation product is prepared as a solution intoluene.

0.02% by weight of the condensation product prepared in the above manneris tested in the Fuel Oil SuspensionTest as hereinbefore described.Results reported as good mean that theadditiveserves to maintain the.sediment in suspension and will not plug filters, burner tips, etc.during use of the fuel. oil.

Example VII v in range oil and evaluated in the Erdco Test. A differ-0.02% bylweight of this condensation productv was incorporated inanother smple of another fuel oil and tested in'the Fuel Oil SuspensionTest heretofore described. When evaluated accordingto this test, thefuel oil containing this additive was reported as' good. As hereinbeforeset forth, this means that the carbon black was maintained in suspensionand did not settle out. On the other hand, a control sample without thisadditive was reported as poor, which means that the carbon black settledout of solution and therefore would plug filters, burner tips, etc.during use.

Example IV 3 002% by weight of this condensation product was entialpressure of 7.1 in. Hg after' 300 minutes was developed in contrast to apressure of 25 in. Hg in less than 100 hours for a sample of the oil notcontaining the additive.

We claim as our invention:

1. A hydrocarbon distillate normally tending to deteriorate containingfrom about 0.00001% toabout 5% by weight, sufiicient to retard saiddeterioration, of the condensation product of art N-aliphatichydrocarbon substituted diallranolamine having fromv about 6 to about 50carbon atoms in the aliphatic hydrocarbon .substituent with the reactionproduct of a terpene and a compound selected from, the group consistingof an alpha,betaunsaturated polycarboxvlic acid, anhydride. and esterthereof, said condensation product having been. formed at a temperatureof'from about C. to about 200 C. and with the use of from about 0.5 toabout 2 equivalents of total acid and potential acid groups in saidreaction product per equivalent ofghydroxyl groupsf'inpthedialkanolamine.

2. A hydrocarbondistillate normally tending todeteriorate containingfrom about 0,0001% to about 5% by weight, suff cient to retard saiddeterioration, of the condensation product of an N- aliphatichydrocarbon sub stituted diall anolamine having from. about 6 toabout 50carbon atoms in the aliphatic. hydrocarbon substituent with the reactionproduct of a terpene and a compound 9 C. to about 200 C. and with theuse of from about 0.5 to about 2 equivalents of total acid and potentialacid groups in said reaction product per equivalent of hydroxyl groupsin the dialkanolamine.

3. A hydrocarbon distillate normally tending to deteriorate containingfrom about 0.00001% to about 5% by weight, suflicient to retard saiddeterioration, of the condensation product formed by condensing at atemperature of from about 80 C. to about 200 C. one equivalent of anN-aliphatic hydrocarbon substituted diaikanolamine having from about 6to about 50 carbon atoms in the aliphatic hydrocarbon substituent withone equivalent of the reaction product of a terpene and a compoundselected from the group consisting of an alpha,beta-unsaturatedpolycarboxylic acid, anhydride and ester thereof.

4. A hydrocarbon distillate normally tending to deteriorate containingfrom about 0.00001% to about 5% by weight, sufiicient to retard saiddeterioration, of the condensation product formed by condensing at atemperature of from about 80 C. to about 200 C. one equivalent of anN-aliphatic hydrocarbon substituted dialkanolamine having from about 6to about 50 carbon atoms in the aliphatic hydrocarbon substituent withone equivalent of the reaction product of a terpene and a compoundselected from the group consisting of maleic, fumaric, citraconic,mesaconic, aconitic and itaconic acids and their anhydrides and esters.

5. A hydrocarbon distillate normally tending to deteriorate containingfrom about 0.00001% to about 5% by weight, sufficient to retard saiddeterioration, of the condensation product formed by condensing atatemperature of from about 80 C. to about 200 C. one equivalent of anN-aliphatic hydrocarbon substituted dialkanolamine having from about 6to about 50 carbon atoms in the aliphatic hydrocarbon substituent withone equivalent of the reaction product of a terpene and maleicanhydride.

6. A hydrocarbon distillate normally tending to deteriorate containingfrom about 0.0001% to about 5% by weight, sufiicient to retard saiddeterioration, of the condensation product formed by condensing at atemperature of from about 80 C. to about 200 C. one equivalent of anN-alkyl dialkanolamine having from 10 about 15 to about 40 carbon atomsin the alkyl group with one equivalent of the reaction product of aterpene and maleic anhydride.

7. A hydrocarbon distillate normally tending to deteriorate containingfrom about 0.00001% to about 5% by weight, sufiicient to retard saiddeterioration, of the condensation product formed by condensing at atemperature of from about C. to about 200 C. one equivalent of anN-alkyl dialkanolamine having from about 15 to about 40 carbon atoms inthe alkyl group with one equivalent of the reaction product of rosin andfumaric acid.

8. A hydrocarbon distillate norm-ally tending to deteriorate containingfrom about 0.00001% to about 5% by weight, sulficient to retard saiddeterioration, of the condensation product formed by condensing at atemperature of from about 80 C. to about 200 C. one equivalent ofN-tallow-diethanolamine with one equivalent of the reaction product of aterpene and maleic anhydride.

9. A hydrocarbon distillate normally tending to deteriorate containingfrom about 0.00001% to about 5% by weight, suflicient to retard saiddeterioration, of the condensation product formed by condensing at atemperature of from about 80 C. to about 200 C. one equivalent ofN-stearyl-diethanolamine with one equivalent of the reaction product ofa terpene and maleic anhydride.

References Cited in the file of this patent UNITED STATES PATENTS2,072,819 Humphrey Mar. 2, 1937 2,080,436 Peterson May 18, 19372,312,732 Salathiel Mar. 2, 1943 2,367,380 Spiller Jan. 16, 19452,371,737 Carson Mar. 20, 1945 2,402,863 Zuidema et a1. June 25, 19462,416,433 Brown Feb. 25, 1947 2,484,010 Bried Oct. 11, 1949 2,524,864Wies et al Oct. 10, 1950 2,540,776 Cadwell Feb. 6, 1951 2,569,495Rheineck Oct. 2, 1951 2,733,224 Smith et a1. Jan. 31, 1956

1. A HYDROCARBON DISTILLATE NORMALLY TENDING TO DETERIORATE CONTAININGFROM ABOUT 0.00001% TO ABOUT 5% BY WEIGHT, SUFFICIENT TO RETARD SAIDDETERIORATION, OF THE CONDENSATION PRODUCT OF AN N-ALIPHATIC HYDROCARBONSUBSTITUTED DIALKANOLAMINE HAVING FROM ABOUT 6 TO ABOUT 50 CARBON ATOMSIN THE ALIPHATIC HYDROCARBON SUBSTITUENT WITH THE REACTION PRODUCT OF ATERPENE AND A COMPOUND SELECTED FROM THE GROUP CONSISTING OF ANALPHA,BETAUNSATURATED POLYCARBOXYLIC ACID, ANHYDRIDE AND ESTER THEREOF,SAID CONDENSATION PRODUCT HAVING BEEN FORMED AT A TEMPERATURE OF FROMABOUT 80* C. TO ABOUT 200* C. AND WITH THE USE OF FROM ABOUT 0.5 TOABOUT 2 EQUIVALENTS OF TOTAL ACID AND POTENTIAL ACID GROUPS IN SAIDREACTION PRODUCT PER EQUIVALENT OF HYDROXYL GROUPS IN THEDIALKANOLAMINE.